Really good for it's price, but sometimes too vague and difficult, you need to repeat long stretches of platforming over and over again which makes it too repetitive. Make main content a bit easier, save big challenges to side conetent and it will be fine.
Visually it's beautiful retro look with many options to make it fit your preferences. Music is good and with visual together they make really unique atmosphere.
I wish there was more levels with unique themes than 3 while one humongous one that takes 3/5 of your experience.
Still had a good time, hopefully next game will be more polished and complete.